Portable observatory



FIG. 1 is a perspective view of a portable observatory showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a side elevational view thereof, with both sides appearing the same;

FIG. 5 is a rear elevational view thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a portable observatory, as shown and described. 